BT home router wide open to hijackers

Updated If you rely on BT for high-speed internet or VoIP, there's a good chance a pair of UK-based researchers know how to enable a backdoor in your router that leaves you wide open to eavesdropping, caller spoofing and other nasty attacks.

The vulnerability resides in the BT Home Hub, one of the UK's most popular home routers, according to Adrian Pastor and Petko D. Petkov. A constellation of bugs in the router, which is made by Thomson/Alcatel, make it possible to bypass the device's password authentication system and gain complete administrative control.

All an attacker needs to do to exploit the weaknesses is lure the victim to a maliciously crafted website, according to this post on the GNUCitizen blog. The exploit doesn't require knowledge of the administrator password.

"The BT Home Hub is vulnerable to an authentication bypass that allows us to make any administrative requests to the router from a malicious website WITHOUT needing username and password," Pastor wrote in an email to The Reg. He and Petkov have confirmed the vulnerability in the BT Home Hub running the most recent firmware. They believe the exploit will work on all Thomson/Alcatel Speedtouch 7G routers.

BT security pros are "actively investigating" the reported holes, according to a statement sent Tuesday. "However, as part of a series of ongoing improvements, this week we began pushing out a new firmware update to Home Hub owners which further improves security in a number of areas," the statement continued. BT didn't elaborate on what the security improvements.

The scope of the vulnerability and the ease in carrying it out means that a remote attacker can quietly gain full administrator control over a device simply by social engineering a user into visiting a website. The exploit makes it possible to steal a user's WPA key, listen in on VoIP calls, steal VoIP credentials or change DNS settings so users are silently redirected to fraudulent websites.

Thomson/Alcatel's Speedtouch 780, a similar router used by Bethere, shares some of the same cross-site-scripting and cross-site-request forgery bugs found on the BT Home Hub. But because it's not vulnerable to authentication bypass, attackers have to know the router's password in order to gain administrative control, Pastor said. ®